Refrigerated vans are generally employed for hauling perishable cargo in crates or boxes without need for cargo tie-down equipment.
On the other hand, cargo such as steel coils are hauled on flatbed trailers and are firmly secured in place as by chains extending over the coils and having their ends secured to suitable anchors along opposite sides of the trailer platform. Although plastic wrappings on the coils may serve as protection from the elements, condensation of moisture on the coils and thermal expansion and contraction thereof are problems to be contended with due to variations in temperature during hauling from the usual 65.degree. F temperature at the mill or warehouse and at the delivery warehouse.